1. Field of the Invention
The present invention relates to a system requiring recording and/or reproduction in real time, and more particularly, to a recording medium for storing real time recording/reproduction information, a method and apparatus for recording and reproducing a real time file based on the real time recording/reproduction information, and a file operating method using the real time recording/reproduction information.
2. Description of the Related Art
In a computer or audio and/or video (A/V) apparatus constituted of a file system for an A/V file required to be recorded/reproduced in real time, control information representing that the A/V file is a real time recording/reproduction file is not recorded in file control information. Thus, it is impossible to reproduce in real time a file comprised of data blocks physically scattered on a recording medium even if they are logically successive.
Here, a conventional file system, as shown in FIG. 1, is comprised of file control information having the length of a file, information on the position of file data, information on the possibility or impossibility of reading/writing a file, etc., and file data stored in positions designated by the file control information. When a file on a disc is read, file control information is first read, and file data in the positions designated by the read file control information is then read and reproduced. Such a method of allocating a block of a fixed size used in the conventional file system cannot guarantee real time reproduction of a file.
That is, recording/reproduction of the conventional file system is described by taking as an example the case in which two files occupy blocks on a disc as shown in FIG. 2. Here, a file A, requiring real time reproduction, occupies blocks 0, 3, 5 and 6 of the disc, and a file B, a general file, occupies blocks 1, 2, 4 and 7 of the disc.
The process for reproducing the file A is as follows.
In the first step, block 0 is read. In the second step, block 3 is searched for. In the third step, block 3 is read and played back. In the fourth step, the block 5 is searched for. In the fifth step, blocks 5 and 6 are read and played back. In the conventional file system, since information associated with real time recording/reproduction is not recorded even when recording a file requiring real time recording/reproduction, a data arrangement for real time recording/reproduction is not considered. Thus, real time reproduction may not be achieved.
That is, the file A (for example, a video file) of FIG. 2 requires real time reproduction, but the conventional file system arranges data files without consideration of the requirement of real time reproduction, thus causing a screen to be interrupted during playback. In order to record/reproduce files in real time, the sum of a seek time and a read time must be smaller than a playback time, as shown in the following expression:
seek time+read time less than playback timexe2x80x83xe2x80x83(1)
In order to prevent a screen from being interrupted, a next block must be searched for during reading and reproducing a current block before the next block is read. However, in an apparatus for driving a disc such as a compact disc (CD) and a digital versatile disc (DVD), the seek time is significantly longer than the read time. Therefore, real time reproduction is impossible if the next block is not physically adjacent to the current block.
To solve the above problems, it is an object of the present invention to provide a recording medium for storing real time recording/reproduction information for real time files.
It is another object of the present invention to provide a method of recording real time recording/reproduction information after real time files are arranged in a minimum contiguous storage block and of reproducing files in real time according to the real time recording/reproduction information.
It is still another object of the present invention to provide a method of copying files in consideration of real time recording/reproduction information, adding the real time recording/reproduction information of original files to copied files, and reproducing the copied files in real time using real time recording/reproduction information.
It is yet another object of the present invention to provide an apparatus for recording a recording/reproduction bit rate as real time recording/reproduction information, for recording a plurality of recording/reproduction bit rates as real time recording/reproduction information when the recording/reproduction bit rate varies for different data sections, and for reproducing files in real time according to the real time recording/reproduction information.
It is still yet another object of the present invention to provide a file operating method of generating a file in which real time recording/reproduction information has been set, expanding data regions, recording and reproducing the file, and performing other file operations.
Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Accordingly, to achieve the above and other objects of the present invention, there is provided a recording medium in which real time files requiring real time recording/reproduction are recorded, wherein real time recording/reproduction information for ensuring real time recording/reproduction of the real time files is stored in a file control information area.
To further achieve the above and other objects of the present invention, there is provided a recording and reproducing method comprising the steps of: (a) arranging and recording real time files requiring real time recording/reproduction on the basis of real time recording/reproduction information for ensuring real time reproduction, and recording the real time recording/reproduction information; and (b) reading and reproducing the real time file data using the real time recording/reproduction information.
To still further achieve the above and other objects of the present invention, there is provided a recording and reproducing apparatus for recording and/or reproducing real time files on a disc using real time recording/reproduction information for ensuring real time recording/reproduction, the apparatus comprising: a codec for compressing and encoding an input bitstream according to a predetermined compression scheme and providing compressed data upon recording, and decoding the compressed and encoded data upon reproduction; a buffer for temporarily storing the compressed data at a recording bit rate using bit rate information included in the real time recording/reproduction information, and transmitting data written on the disc to the codec at a reproduction bit rate; a signal processor for converting the data stored in the buffer into a signal suitable for recording and transmitting the converted signal together with real time recording/reproduction information onto the disc upon recording, and reproducing data read from the disc according to the real time recording/reproduction information recorded on a predetermined area of the disc; and a controller for controlling the driving of a servo mechanism including a spindle motor according to bit rate information of the real time recording/reproduction information.
To still yet further achieve the above and other objects of the present invention, there is provided a method of operating a file for a system capable of writing and rewriting real time files to which real time recording/reproduction attribute information is assigned, wherein the real time files are operated in correspondence with any one process among a real time file creation process, area allocation process, a recording process, a reproduction process, a deletion process, and a closing process using the real time recording/reproduction attribute information.